Smc3 problem

Mi rig was working fine, but started to do some dips in one side, like loosing power for one second.
This only occurs when going down, in gravity direction, i know my rig is a bit heavy in that side.
It only happens in large movments.
Allready changed ibt2, power supply, and even motor.
In thinking of psu not delivering all power, I measured voltaje when this occurs and volts on positive of ibt2 going to psu rise at 34v on that moment, fast spinning of the motor acts like a generator. So I put a 50v 30a Schottky diode, but nothing changed. Tested a lot of combinations in PID, but still happens.
Heres a pic.

Pic

Pic 1

Sine and motion

When the overshoot happens, voltaje meter show 37v at power side of the ibts. Motors are acting like a generator, May be shooting them down for an instant, really dont know how they work. Its on fast change of direction, on that side rig is heavier, but this didnt happened before. Bad motor?
By the way, im using dofreality SFUs, they dont lock up in change directions

Well, i think i figuered out. Heres the deal.
In order to mitigate a small overshoot, thinking of a over voltaje spike at psu, i put and schottky diode at the positive wire of the ibt2 power in, like dofreality does in their rigs, but this caused to block outcomming spikes to the psu, but this voltaje must go somewhere, so ibts absorved and shuts off for a while. Dofreality uses cytron md13s, that hace regenerative brakes, so they can handle that spikes, ibts no.
I get rid diodes and everything is working like before. Im going to put sone large capacitors on H-Bridges to help and give the system an extra punch.
Ordered 3 x md13s, to change bts7960.
Mi rig is heavy at front, i think my 150 watts motors a bit underpowered, but its all i can find in my country. In the future im going to buy dof reality New geared motors, but they are 700$ plus 275 shipping...

My rig

Sfus